This invention relates to digital n-state memory latches. More specifically it relates to n-state memory latches comprising n-state reversible inverters.
Multi-valued or n-state digital memory elements can be applied in digital circuit applications where the temporary storage of n-state digital information is required.
There are known and different ways to retain binary digital information. There are known physical effects that put a material in one of two different physical states. A capacitor holding an electrical charge may represent a binary 1 state, while the capacitor without a certain electrical charge may represent a binary 0. Different magnetic states (such as applied in magnetic disk drives) are another example. Another example is the optical reflective state of a material such as applied in optical disks (such as CD-ROMs).
Other binary devices use logical effects. By applying binary logical functions in feedback configurations, the resulting (usually electronic) circuit retains information about its previous switching state or states. Binary flip-flops and latches are well known examples. The memory effect depends mainly on the applied logical functions.
One way to implement binary latches is by using inverters in feedback. These latches may be called re-circulating binary latches.
N-state or n-valued memory devices using two 2 input/single output n-state logic functions are disclosed by the inventor in U.S. patent application Ser. No. 11/139,835, filed on May 27, 2005.
An n-valued digit (with n an integer greater than 2) has inherently more information content than a binary digit. Accordingly, a memory device that can retain an n-valued digit retains more information than a binary memory device. Multi-valued sequential digital (memory) devices can also facilitate the usefulness of other multi-valued logic circuits.
An n-state or n-valued datum or symbol is a single element or signal representing one of n states. It is known that an n-state symbol can be represented by 2 or more lower valued symbols. However, an n-state or n-valued symbol herein is intended to mean a single symbol that is represented by a single signal and wherein a plurality of signals represent a plurality of symbols, unless explicitly identified as meaning something else. An n-state latch in general will mean herein to be a device that will store an n-state symbol in its n-state symbol form and not as a plurality of lower valued or lower state symbols.
In some situations, it may be beneficial to have n-state latches which can be implemented with n-state inverters, which may be easier to use than the two 2-input/single output n-state logic functions with feedback. N-state latches from n-state inverters using signals which are independent instances of a physical phenomenon are unknown.
Accordingly, new and improved devices and methods to realize n-state latches from n-state inverters are required. Latches with n-state inverters using signals which are independent instances of a physical phenomenon are also required.